In Hong Kong, 999 is an emergency hotline number, similar to 911 in other countries.When people encounter emergencies in Hong Kong, such as fires, medical emergencies, police incidents, etc., they can call 999 for help. However, 999 does not represent a Hong Kong ambulance per se, but is a number used to contact the relevant emergency services. Once a 999 call is received, the relevant emergency services, including the ambulance service, will be mobilized to the location where help is needed.